Question: Simplify the following expression: $ q = \dfrac{2}{10k + 9} + 4 $
Explanation: In order to add expressions, they must have a common denominator. Multiply the second expression by $\dfrac{10k + 9}{10k + 9}$ $ \dfrac{4}{1} \times \dfrac{10k + 9}{10k + 9} = \dfrac{40k + 36}{10k + 9} $ Therefore $ q = \dfrac{2}{10k + 9} + \dfrac{40k + 36}{10k + 9} $ Now the expressions have the same denominator we can simply add the numerators: $q = \dfrac{2 + 40k + 36}{10k + 9} $ $q = \dfrac{40k + 38}{10k + 9}$